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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds meaningful context beyond that: the 'repo' scope requirement, and the restorable_until semantics (the repo is purged automatically after that date), which is a behavioral trait an agent needs to reason about timing.

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?

Front-loaded with the core action and scope, then auth requirement, then return shape. Dense but nearly every clause carries information; the only mild redundancy is repeating the `all` semantics already in the schema.

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?

With no output schema, the description supplies the return shape ({total_count, repositories:[...]}) plus scope, auth scope, and purge timing. An agent has everything needed to call it and interpret results.

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% and the single `all` parameter is already documented in the schema as 'Site admins only: every deleted repository on the instance'. The description restates this rather than adding new syntax or format detail, so 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 (list deleted repositories) and immediately scopes it: personal ones plus orgs you own, with a site-admin exception. The phrase 'you can restore or purge' signals the sibling operations (restore_repo, purge_repo, delete_repo) it feeds, so the agent can place it without opening schemas.

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?

Clearly frames the use case (finding repositories eligible for restore or purge) and notes the admin-only `all: true` path, giving good context for when this tool applies. It stops short of naming alternatives or stating when NOT to use it, so it is strong context without explicit exclusion rules.

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