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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful context beyond them: sort keys are drawn from cached GitHub data and "GitHub tasks are not synchronized", warning the agent that freshness may lag, plus "self-reported" availability indicates unreliable data.

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 tight sentences: purpose first, then sort options, then the freshness caveat. No filler, and the most important scoping information is front-loaded.

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 read-only search with no output schema, the description covers what it searches, how to sort, and the data-freshness caveat. It never mentions pagination (page max 100) or the shape of returned listings, which is a minor but real gap for an agent issuing repeated queries.

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%, so the description must carry the load, and it does: it maps query/topic/capability/availability to search facets and explains what each sort key means (cached stars, forks, contributor accounts, latest push, listing dates, name), matching the enum values. It omits "page" and does not explain the availability enum values, so it falls short of full compensation.

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 ("Search") and a precisely scoped resource ("published directory listings") with the facets it searches over: keyword, topic, capability, and self-reported availability. This clearly separates it from get_swarm (single-record retrieval) and the register/update mutation siblings without needing to name them.

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 the verb and facets, but there is no explicit when-to-use statement, no condition distinguishing it from get_swarm, and no when-not guidance. The closing caveat about GitHub sync is a data-freshness note rather than routing guidance.

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