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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower, yet the description adds real context: the check is offline, and crucially warns that a valid signature only proves signing by the embedded key, not by a trusted signer. This security caveat is exactly the kind of behavioral disclosure an agent needs. It doesn't describe return shape or failure modes, but an output schema exists.

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 sentences, front-loaded with the core action, then the conditional report behavior, then the signer requirement. Every sentence carries non-redundant information and nothing is padded.

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 verification tool with good annotations, full schema coverage, and an output schema, the description covers what is checked, the optional parameters' roles, and the trust caveat. An agent has everything it needs to call it correctly.

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%, setting a baseline of 3, but the description adds semantic meaning beyond the schema: it explains the report/attestation coverage relationship and the security implication of expected_public_key. That elevates it above the baseline.

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 ('verifies' a 'Settlens evidence attestation') and names the exact cryptographic operation (ed25519 signature check plus report integrity/coverage). It is clearly distinguishable from siblings like verify_report and verify_payment_signature because it defines the attestation-specific scope.

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?

Gives conditional usage: the report parameter is only relevant 'when the report is supplied', and expected_public_key should be passed 'to require a specific signer'. It does not explicitly name alternative sibling tools or state when-not to use this one, so it falls 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.