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

Annotations already declare non-read-only, non-destructive, and idempotent; the description adds real side-effect detail beyond them: RESOLVED stamps resolved_at, a status message is appended to the thread, and the issue is never deleted ('Write tier'). One tension worth noting: an appended thread message implies a repeated call leaves an extra artifact, which sits awkwardly with idempotentHint=true, but the terminal state is still the same so it falls short of a true 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?

Front-loaded with action plus endpoint, then progressively finer detail (valid states, side effects, safety), and 'Write tier' is a compact safety signal. The re-listing of the enum values duplicates the schema's enum, a minor redundancy, but every other clause 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?

For a two-parameter mutation with no output schema, the description covers the state machine, the notable side effects, and the non-destructive guarantee — enough to call it correctly. Missing links are the return shape and any permission/authorization requirements for changing an issue's status.

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 0%, so the description must carry parameter meaning; it enumerates the five status values and explains the RESOLVED special case, which is genuinely useful. It leaves the semantics of ACKNOWLEDGED vs IN_PROGRESS unexplored and says nothing about issue_id format, so the compensation is partial.

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 (change status), the resource (issue), and the underlying endpoint (PUT /issues/:id), and enumerates the exact target states. This cleanly separates it from sibling tools such as tascan_reply_issue, tascan_raise_issue, and tascan_list_issues without the agent needing to open the schema.

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 the RESOLVED-specific note (resolved_at stamping), which tells an agent the relevant condition for the resolution path. However, it never states when to prefer this over related siblings like tascan_reply_issue or tascan_auto_resolve, nor any prerequisites or exclusions — the agent must infer routing.

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