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

Discloses that SaSame holds no funds, timestamps and signs envelopes with ed25519 for offline verification, and returns a signed receipt. This adds significant context beyond the annotations (readOnlyHint false, etc.). No contradiction.

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 concise sentences front-loading purpose, usage, and key behavioral details. No fluff, every sentence earns its place.

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?

Covers purpose, usage, behavior, and return value. Lacks details on receipt format or verification steps, but given schema coverage and annotations, it is sufficiently complete for an agent to use.

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 covers 100% of parameters with descriptions. The description does not add extra meaning to parameters beyond what the schema provides. Baseline score is appropriate.

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 clearly states the tool opens a usage/budget meter in SaSame's append-only ledger. It uses specific verb 'Open' and resource 'usage/budget meter', distinguishing it from siblings like meter_charge and meter_status.

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?

Describes when to use: 'when a principal/orchestrator wants to give a sub-agent a capped budget'. It also clarifies what it is not (payment processor). Lacks explicit exclusions or alternative tool references, but the guidance is clear.

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