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

Annotations already mark it read-only/non-destructive, and the description adds meaningful behavior: data is cached, only public repos are supported, freshness is tied to the most recent commit, and null is returned on cache miss. No annotation contradiction.

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?

A single, front-loaded sentence carries the core operation and both important qualifications (cached, public, most recent commit, null behavior) with no 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?

For a simple read-only lookup with two fully documented parameters, the description covers input, scope, and return behavior (Markdown or null) despite no output schema. It could be slightly more complete by pointing to the generation sibling on cache miss.

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% for owner and repo, so baseline is 3. The description does not add parameter-level syntax or format details, but none are needed beyond the schema's owner/repo definitions.

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 states a specific verb ('Return'), a precise resource (cached AI explain-codebase Markdown for a public repo), and a scope qualifier ('most recent commit'). The 'cached' and null-return behavior clearly differentiate it from the uncached gluecron_explain_repo sibling.

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 implies use case—fetch a cached explanation when one exists—and signals cache miss with null, but it never explicitly names an alternative such as gluecron_explain_repo or states when to prefer it. Usage context is present but exclusion/alternative guidance is left to inference.

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