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

Annotations already declare readOnlyHint=true and destructiveHint=false; the description reinforces this with 'writes nothing' and adds genuinely new behavioral context — exactly what is returned, that analyze produces 'differences and a full new version', and that basis=actual depends on git read access. It stops short of describing pagination or output format, but the safety profile is fully covered.

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 tool's purpose and the 'writes nothing' guarantee before the parameter mapping, and every clause carries information. It is dense in a single block rather than scannable segments, but there is 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?

With no output schema, the description carries the return-value burden and does so by listing the returned artifacts and noting the git-read dependency for basis=actual. The one required param is covered; only minor edges like ID/key precedence and chatLimit behavior are left entirely to the schema.

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%, so the baseline is 3, but the description earns extra credit by explaining what mode=analyze actually yields (differences plus a full new version) and by grounding both enum params in the user's own words. It does not touch ID vs. key or chatLimit, which the schema already handles.

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 (returns the context for updating a task's/bug's spec) and immediately enumerates the payload: spec, feature, recent chat, code summary, and workspace guidelines. The explicit 'writes nothing' plus the task/bug scoping distinguishes it from the sibling feature_spec_sync.

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?

Maps user intent directly onto parameter values: mode=analyze is for 'check, compare, propose' requests, mode=apply is 'when the user asks to update or sync'; basis=requirements means 'from the chat' and basis=actual means 'from the code, as built'. An agent can select values straight from the user's phrasing with no inference.

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