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

With no annotations, the description carries the full burden and mostly delivers: immutability per tenant, rotation via new key_id, conflict on duplicate key_id, private key must stay local, and the fee-approval prerequisite. It omits auth/permission scope and any rate or latency expectations, so it falls just short of exhaustive.

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, then constraints, then prerequisites; every sentence conveys actionable info. Dense but not padded, though the trailing fee-approval sentence reads as an afterthought.

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?

No output schema exists, but the description compensates by naming the return values (key_id, registered=true) and covering mutability, rotation, conflicts, and call prerequisites. Adequate for a 2-param registration tool, though it lacks authorization/permission context.

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 the schema already documents key_id uniqueness/rotation and PEM/key-size rules; the description largely echoes those rather than adding new parameter-level detail. Baseline 3 applies when the schema does the heavy lifting.

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 ('Registers an RSA public key ... used to sign payment-decision requests') with concrete constraints (2048-bit+, PEM). It explicitly distinguishes itself from siblings like check_* tools and payment authorization, so an agent can route correctly.

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 explicit sequencing ('Use before decide_supplier_payment'), a consistency requirement ('same tenant/paying wallet for registration and decision'), negative boundaries ('not a supplier check, API-key creation or payment authorization'), and a prerequisite (approve the registration fee first).

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