perseus_prompt

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

The description adds value beyond the readOnlyHint annotation by stating 'Read-only; rendered as-is into the output', which clarifies the behavioral impact. This extra context on how the prompt is treated and its output behavior justifies a score above 3.

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

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

The description is three sentences, each serving a distinct purpose: defining the tool, giving usage examples, and stating behavioral traits. No redundant content.

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

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

Given the tool's simplicity (one optional parameter, read-only, with output schema), the description covers all aspects: purpose, usage, behavior, and output. It is complete for effective selection and invocation.

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

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

Schema description coverage is 100% for the single optional parameter 'args', and the description does not add extra meaning beyond that. The baseline of 3 applies as the schema already documents the parameter adequately.

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

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

The description clearly states the tool defines a system prompt block for instructing the AI assistant, specifying the resource ('system prompt block') and the action ('define'). It distinguishes from siblings by focusing on prompt definition, and gives concrete examples of use (behavioral rules, memory hygiene gates).

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

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

The description explicitly says 'Use to set behavioral rules, memory hygiene gates, or context interpretation guidelines', providing clear context for when to use. However, it does not mention when not to use or explicitly contrast with sibling tools, preventing a score of 5.

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