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

Annotations already indicate read-only, closed-world, non-destructive behavior, but the description adds meaningful context beyond them: no login required, indexed rather than live data, possible metric staleness, and third-party post text in results. This gives the agent a clear behavioral and data-quality picture.

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 tightly written sentences, front-loaded with the core purpose. Every clause adds useful scope or data-quality context without repetition.

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?

With no output schema, the description compensates by describing result content: source links, stored engagement metrics, and third-party post text. It also covers key limitations around indexed data, staleness, and authentication, making it complete enough for correct 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%, so parameters are already well documented. The description reinforces the topic and high-performing concepts but adds no syntax, default, or format details beyond the 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?

The description uses a specific verb and resource: 'Find high-performing public X posts in Postel's index by topic.' It clearly distinguishes the indexed search scope from live X and complete archives, but does not explicitly differentiate from siblings like list-posts or get-post.

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?

Usage is implied by 'by topic' and the high-performing focus, and the description gives useful scope exclusions ('not live X or a complete archive'). However, it does not state when to choose this tool over sibling tools such as list-posts or get-post.

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