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

Annotations only declare idempotency and non-destructiveness; the description adds substantial non-annotation behavior: overwrite refusal, no false human authorship/approval claims, approved-source-ID requirement for attachments, dependency resolution gating, and immutable history per mutation. These are exactly the mutation semantics an agent needs and cannot get from structured fields.

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?

Six compact sentences, purpose front-loaded, and the prefill constraint placed early where it matters most. No filler, though the closing line about immutable history is the least load-bearing of the set.

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 nested, four-required-parameter mutation with no output schema, the description covers refusal semantics, evidence constraints, dependency gating and history preservation. It is nearly complete, missing only revision-conflict/error handling and idempotency-key reuse guidance that the schema only partially supplies.

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 50%, so the description must carry part of the load. It clarifies prefill vs replace semantics, that comments and source markers accompany changes, and that evidence must reference approved source IDs, but it says nothing about idempotencyKey reuse or expectedRevision/payloadHash conflict behavior, leaving those to the schema text.

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 ('Save field contributions') and enumerates what is carried with them (provenance, source markers, comment, revision protection). It is clearly the write-side contribution tool, distinguishable from read/review siblings like read_contribution_history or request_contribution_review, though it never names those siblings explicitly.

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 prefill for empty fields; it refuses overwriting existing work' gives concrete when-to-use guidance tied to the intent enum, and 'Resolve changed dependencies before re-review' states a precondition. No explicit alternative-tool routing is offered, so it stops short of a 5.

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