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

Goes well beyond annotations: discloses that the fingerprint is registered in a public register at ptpge.org/f with the same-configuration→same-entry property and irreversibility, matching readOnlyHint=false and idempotentHint=true. It also explains validation-first issuance and the exact error shape (error=not_fingerprintable + needs_disambiguation), which no annotation conveys.

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-loads the side effect and irreversibility first, then the computation, then the return shape, then the error contract — a sensible order. It is dense and peppered with spec references (SD-0040, SD-0083, SD-0108) that add length without much decision value for an agent.

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 burden and does: it enumerates both returned profiles, the strict spec ⊂ request containment, the optional visuals payload, and the error/validation contract. An agent has enough to invoke it correctly and handle failures.

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?

Adds real meaning to 'bindings' beyond the schema: every required axis must be bound (or envelope-implied and then written into the identity) and every surface must match a bound setup face. 'visuals' is fully covered by its schema description and is not repeated, which is fine at 67% coverage, but 'product' semantics (URI vs path resolution) remain unelaborated.

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?

Specific verb+resource: 'Compute the canonical ptpge-cfs/1 serialization and SHA-256 fingerprint of a resolved product configuration', with the returned shapes ('spec' and 'request' profiles) spelled out. This distinguishes it clearly from siblings like ptpge_expand_fingerprint and ptpge_validate_config by naming the artifact it produces and its role as quote/order/cache key.

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?

States the context of use (vendor-neutral identity for quoting/ordering/caching) and gives an explicit operational rule for the failure path: on error=not_fingerprintable, put needs_disambiguation questions to the user verbatim and call again; never guess. It never explicitly names an alternative tool (e.g., 'to reverse this, use ptpge_expand_fingerprint'), so sibling routing remains implicit.

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