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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=true, idempotentHint=true, destructiveHint=false). The description adds no new behavioral context such as rate limits, authentication needs, or pagination behavior; it only repeats return fields which are likely in the output schema. No contradiction arises.

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 exactly two sentences, front-loaded with the main action and resource. It includes the return fields and a usage hint without unnecessary fluff. Every sentence earns its place.

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?

Given the simple tool, complete schema coverage, presence of an output schema, and strong annotations, the description provides the essential context for an agent to select and invoke the tool. The usage hint adds extra value beyond the structured data.

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%. The schema already provides detailed descriptions and examples for query, sort, and per_page. The description does not add any extra meaning or clarification beyond what the schema offers, so it stays at the baseline.

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 the specific verb 'Search' with the resource 'GitHub repositories' and specifies the search scope 'by keyword.' It clearly distinguishes from sibling tools like search_code (which searches code content) and get_repo (which fetches a single repo).

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 explicitly states when to use this tool: 'Use when exploring projects or finding code implementations.' This provides clear usage context. It does not mention when not to use it or alternatives, so it misses the full 'when/when-not/alternatives' guidance.

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