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

Annotations already declare this is a non-read-only, non-destructive, non-idempotent write with open-world access. The description adds real behavioral detail beyond that: it replaces a specific marker, and it clears the score so a re-score is required afterward — a side effect an agent would otherwise miss.

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?

Three short sentences, front-loaded with the mutation itself, then the precondition, then the side effect. Every sentence carries distinct information with no padding.

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 no-output-schema mutation tool, the description covers the write target, the marker replacement, the precondition and the score-clearing side effect. The main residual gap is the return value/confirmation format, which is minor given the tool's simplicity.

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 url, title, brief_id and claim_id are all documented. The description's note that claim_id comes from suggest_sources largely repeats the schema's own wording, adding little new meaning. Baseline 3 is appropriate.

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: writes the user-chosen source into the draft at the claim as a markdown link, replacing the [SOURCE NEEDED] marker. This is concrete enough to separate it from sibling tools like suggest_sources or assist_draft.

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?

'Only call after the user picked it' gives an explicit precondition, and pointing to suggest_sources identifies where claim_id originates, implicitly routing the agent through that tool first. It does not state what to do if the user changed their mind or if the marker is absent, but the core when-to-use guidance is clear.

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