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

Annotations already declare the write behavior (readOnlyHint=false), idempotentHint, and openWorldHint. The description adds valuable context on top of these: it is a one-call publish without an account/key, gaps are allowed and expected, and the actual value for the payer of a filing with gaps. It doesn't describe the response or failure modes, but that's a minor omission given the annotation coverage and rich behavior notes.

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?

The description is front-loaded: the first sentence nails the purpose and sibling distinction, then the next sentences add prerequisites and gap semantics. Every sentence has a purpose and the tone is natural. It's a little long with the 'A filing with declared gaps...' paragraph, but even that sentence adds a useful normative expectation, so it stays effective rather than bloated.

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 tool with 5 parameters (2 required), a nested object, and no output schema, the description covers the necessary usage context: what the tool is for, how it relates to the sibling, the prerequisite list, the authorization condition, the gap-filling behavior, and even the business reason behind it. Nothing an agent requires to invoke it 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 coverage is 100% and the schema already documents every parameter. The description adds a little extra semantic nuance (entity is the party, not the agent, and gapPlan is for false controls, plus the hint to derive control ids from baseline_controls), but it does not go far beyond the schema. This matches the baseline score of 3 for high schema coverage.

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?

The description states a specific verb–resource pair ('File your operator's control-baseline attestation') and immediately contrasts it with the sibling tool counterparty_control_baseline: 'That tool asks what controls the OTHER side runs; this one publishes what YOUR side runs.' This gives the agent an unambiguous, scoped purpose and clear sibling differentiation.

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?

It explicitly says when to use this tool (file your own controls) versus the alternative (counterparty_control_baseline for the other party), names the prerequisite resource (get control ids from baseline_controls first), and imposes an authorization constraint ('Only file for a party you are actually authorised to speak for'). This provides the agent with both the context and the exclusions.

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