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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint, covering the safety profile. The description adds valuable behavioral details: it counts against the workspace's Pinterest read limit, fails with rate_limited (with retry_after_seconds) when spent, and returns not_found for unknown accounts. This goes beyond the annotations and helps the agent anticipate failures.

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?

The description is three sentences of concise, front-loaded content. It leads with the purpose, then usage context, then return value and error behavior. Every sentence adds distinct value, with no filler or redundancy. The structure is clear and scannable.

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?

Despite the absence of an output schema, the description specifies the return structure (id, related_term_count, related_terms_list) and error conditions. Combined with the schema's parameter documentation and annotations' safety profile, an agent has all necessary information to invoke the tool correctly. Nothing critical is missing.

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% – all parameters are fully described in the input schema. The description mentions 'seed keywords' which aligns with the terms parameter but adds no new semantic meaning beyond the schema. Since the schema already documents parameters comprehensively, the baseline of 3 is appropriate; the description does not compensate for any gap.

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's purpose: 'Look up the search terms Pinterest associates with your seed keywords.' It uses a specific verb and resource, and immediately distinguishes itself from create_pin by explaining it's for drafting descriptions or choosing related_terms. This differentiates it from other tools like list_pins and create_pin without ambiguity.

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?

The description provides explicit guidance on when to use the tool: 'Use while drafting a description or choosing related_terms for create_pin' and 'Not needed for publishing itself.' This gives clear context and excludes uses for publishing. However, it does not explicitly name alternative tools beyond create_pin, so it falls short of a perfect score for exhaustive alternatives.

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