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

With no annotations, the description carries the burden. It discloses that this is a lightweight read operation returning summary metadata and top holdings, and does not load full content. This communicates low-cost, non-destructive behavior, though it omits details like pagination or whether filters are required.

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?

Three tightly written sentences: main purpose, return content, and recommended usage. Every sentence earns its place with no repetition or filler.

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?

The output schema covers return structure, and the description explains what the index contains and when to use it. The main gap is parameter guidance, but for a simple, all-optional-filter index tool, the description is largely complete.

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 0%, and the description does not explain any of the four parameters (date_to, date_from, fund_type, manager_slug). While names imply filters, there is no mention of accepted formats, semantics, or defaults, so the agent gets no added value beyond the raw schema.

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?

Description opens with a specific verb+resource: 'Get a lightweight summary index of pension fund holdings reports.' It clearly distinguishes itself from siblings by specifying it returns allocation metadata and top holdings 'without loading full content', and explicitly directs full-content needs to `read_holdings_report`.

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?

States an explicit use case: 'Use this for quick discovery to decide which reports to load in full with `read_holdings_report`.' This also names the alternative tool for full reports, providing clear when-to-use vs. when-not-to-use guidance.

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