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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld). The description adds genuinely non-structured context: 'Facts only, no grade, no guarantee' sets output expectations, and 'One free call' plus 'no key' discloses call limits and auth needs.

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 the decision question, then three tight clauses enumerating what is returned. Dense but nearly every phrase maps to a real fact; the run of parentheticals slightly taxes readability but nothing is filler.

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 and no annotations gap, the description enumerates the return content (proven history, declarations, conduct) and the input forms, which is enough for an agent to call it correctly. Minor gap: it doesn't say whether both inputs can be combined or which wins if both are passed.

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 0% for both parameters, so the description carries the load, and it does: 'A PazAIr agent_id, or any Word Pass URL' maps the two unlabeled params (agent_id, url) to their accepted forms and notes either is optional in practice.

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 ('check_agent') with an explicit scope: proven facts, self-declarations, and conduct. It directly names and differentiates itself from the sibling check_word_pass ('wider than check_word_pass, which checks only the pass'), so an agent can pick between them 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?

'One free call before you work with an agent you do not know' states the triggering condition, and the parenthetical identifies the alternative tool and its narrower scope. The 'Free, no key' note tells the caller there is no auth prerequisite.

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