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

Annotations already mark the tool as read-only and idempotent, so the safety profile is clear. The description adds value by revealing pagination and the specific filter dimensions (status, category, core/supplementary, in-force-on-date), which are beyond what annotations provide. No contradiction with annotations.

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?

Two sentences with no filler; the core purpose is front-loaded in a memorable question. The workflow second sentence is slightly convoluted—'emumerate each instrument with list_provisions' could be misread as listing instruments rather than provisions—but it remains compact and useful.

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?

An output schema exists, so return structure needs no description. The description covers the main filter categories, pagitation, and connects to the relevant sibling tools in a workflow. Minor gaps: default ordering, whether filters combine additively, and the precise meaning of 'in force' are not stated, but these are not critical for calling the tool correctly.

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 only 33%, so the description must compensate. It does so by mapping filters to parameters: status, category, core/supplementary (is_core), in-force-on-date, and pagination (limit/cursor). It does not clarify the exact format of limit/cursor or category values, but the schema covers status and in-force-on-date formats.

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 opens with 'What is in the corpus?' which immediately frames the tool's purpose: listing instruments in the corpus. It names the specific resource (instruments), the operation (list), and key behaviors (paginated, filterable), and clearly distinguishes it from siblings by outlining a workflow with list_provisions and get_provision.

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 gives explicit usage guidance: 'For corpus-coverage questions, filter by category here' and suggests a workflow using list_provisions and get_provision. It implies this tool is for broad corpus exploration rather than targeted retrieval, though it does not explicitly state when not to use it or contrast with search tools.

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