perseus

perseus_profile

Read-only

Defines the context profile for a document, setting the context target and memory posture used by automatic memory injection. Use @profile at the top of a document.

Instructions

Select the per-model context profile for this document (#608): sets the context target and memory posture (on_demand/relevant/always) used by the automatic memory injection layer. Use at the top of a context document, e.g. @profile claude-sonnet-4-6. Unknown names fall back to the default profile. First-wins (#627): with multiple @profile lines only the first non-fenced one governs — later banners are marked ignored, and @profile inside a code fence is documentation, never a directive. Read-only.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "perseus_profile"
  }
}

Input Schema

Name	Required	Description	Default
`model`	No	Model name (or context-window class) whose profile to resolve, e.g. claude-sonnet-4-6; unknown names fall back to default

Schema Changelog

Changes observed during successful MCP inspections.

Addedv1.0.14Jul 7, 2026

TDQS

A4.7/5.0

Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description goes beyond the readOnlyHint annotation by disclosing specific traits: the first-wins rule with multiple @profile lines, ignored later banners, fallback to default for unknown names, and that @profile inside a code fence is documentation. This adds significant behavioral context.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise and well-structured: it starts with the core purpose, provides a usage example, then lists behavioral rules. Every sentence adds necessary information without redundancy.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Despite having no output schema, the description fully covers the tool's behavior for a simple configuration tool. Given the single optional parameter and the presence of annotations, the description completes the picture.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is high (100% for the single parameter 'model'). The description adds value by clarifying that the model name can be a context-window class and reiterates the fallback behavior, though it largely echoes the schema's description. The extra context warrants a score above the baseline.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool selects a per-model context profile for a document, specifying it sets the context target and memory posture. It uses specific verbs ('selects', 'sets') and identifies the exact resource (per-model context profile), making it distinct from sibling tools.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly instructs to use at the top of a context document with an example (@profile claude-sonnet-4-6). It also provides important behavioral notes like the first-wins rule and fallback behavior. While it doesn't explicitly state when not to use it, the context and example are clear.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.