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

readOnlyHint is already declared, and the description corroborates it with 'writes nothing', which resolves the potential ambiguity that mode=apply might imply a write. It also discloses the dependencies of the returned content (code summary requires basis=actual and git read access). It stops short of describing pagination or response shape, but adds meaningful context beyond the annotation.

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?

Purpose and the 'writes nothing' constraint are front-loaded, followed by compact mode/basis breakdowns. It is dense but every clause carries information; the run-on use of semicolons is slightly harder to parse than ideal.

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?

There is no output schema, yet the description enumerates the returned context (spec, feature, chat, code summary, guidelines), covers both enum parameters and their interactions, and confirms the read-only behavior. Nothing needed to invoke this tool correctly is missing.

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 schema already documents all five params, setting the baseline at 3. The description adds user-intent phrasing for the enum values ('check, compare, propose', 'the user asks to update or sync', 'from the chat', 'as built') that maps natural-language requests onto parameter values, giving it an edge over the schema alone.

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 or bug's spec') and then enumerates exactly what is returned: spec, feature, recent chat, code summary, and spec-update guidelines. The task/bug scoping implicitly distinguishes it from the sibling feature_spec_sync, and 'writes nothing' pins down the nature of the operation.

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?

Explicitly routes the agent by mode: 'mode=analyze - for "check, compare, propose" requests' versus 'mode=apply - when the user asks to update or sync'. The basis param is similarly disambiguated ('from the chat' vs 'from the code, as built'), which is exactly the when-to-use guidance an agent needs.

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