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

Annotations already cover the safety profile (readOnly, non-destructive, idempotent, open network). The description adds that results include descriptions, latest versions, and download counts, which is genuinely useful given no output schema, but it says nothing about result-count limits, pagination behavior, or empty-result handling even though a 'page' param exists.

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 lean sentences, front-loaded with the action and data source, then the return contents. Nothing is repeated and nothing is padding.

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?

For a three-parameter, read-only lookup with full schema coverage and no output schema, this is close to sufficient: the agent knows the domain, the input, and roughly what comes back. Only pagination semantics and the search-vs-fetch boundary are left implicit.

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 coverage is 100% and every parameter carries its own description plus an enum on 'sort', so the schema already does the semantic work. The description adds no meaning beyond 'query is a keyword', so the baseline 3 applies.

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?

States a specific verb and resource (search the Hex.pm registry for Elixir/Erlang mix packages by keyword) and even summarizes the payload shape. It is clearly a keyword-discovery tool, distinguishable in kind from get_package/get_release, though it never names a sibling to sharpen that contrast.

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 phrase 'by keyword' implies the entry condition (you have a search term rather than an exact package name), but there is no explicit when-to-use, when-not-to-use, or pointer to hex_pm_get_package once you have an exact name. Usage must be inferred.

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