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

Annotations only declare readOnlyHint=true; the description goes further by disclosing the enumerated lifecycle states, clarifying that a live proof reads "active", and flagging the authentication prerequisite and the start_login dead end. That is meaningful behavioral context beyond the annotation, though it says nothing about rate limits or failure modes.

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?

Front-loaded with purpose and return states, then the access note. Two short blocks with no filler, though the authentication paragraph could be tightened slightly.

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?

With no output schema, the description carries the return-value burden and does so by enumerating the possible statuses. Auth requirements are also covered. Complete enough for a single-parameter read tool, with only minor gaps around error cases.

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 there is one parameter whose description already explains the handle/verification-ID formats. The description repeats the same handle syntax, adding no format or validation detail beyond what the schema provides, so the baseline 3 applies.

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 (Get) and resource (proof status), specifies the identifier forms accepted, and enumerates the possible outcome states (active/suspended/expired/revoked). This is enough to distinguish it from siblings like validate_proof or list_revoked_proofs without opening a schema.

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?

Tells the agent what input selects this tool (a proof handle or verification ID) and adds an explicit access precondition: a Proof account is required, the client must be authenticated via /mcp, and start_login does NOT unlock this tool. No direct when-to-use-vs-validate_proof comparison, 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.