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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so "Read-only" in the description is largely redundant. The metric enumeration adds useful context about what the call surfaces, but nothing is said about behavior on an unknown repository name, empty results, or the cost of the open-world lookup.

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?

Three short sentences, front-loaded with the purpose and metric contents, with usage guidance immediately after. The trailing "Read-only" is the only wasted clause since the annotations state it three ways already.

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 one-parameter read tool with no output schema, listing the metric categories is the most valuable thing the description can do, and it does so. It falls short only on edge-case behavior and on not routing the agent to list_repositories when the repository name is unknown.

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 the single parameter already documents both the short name and the org/name form with examples. The description adds no further meaning such as case sensitivity, whether partial or fuzzy matches resolve, or what happens when the owner is omitted — baseline 3 applies when the schema does all the work.

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 names a specific verb and resource ("Get detailed metrics for a specific repository") and enumerates the metric families returned: deployment frequency, PR cycle time, contributor count, code health. That distinguishes it from sibling summary/trend tools, though it never names list_repositories as the browsing counterpart.

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?

"Use this when asked about a specific codebase" gives an implied selection rule versus the list_* siblings, but there is no explicit when-not guidance (e.g. use list_repositories to discover names first, or use get_org_health for aggregate views). The agent must infer the boundary from sibling names alone.

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