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

Annotations already establish readOnly, idempotent, non-destructive behavior, so the bar is low. The description adds real domain context beyond them: found_by distinguishes a crawler from an AI search vendor, and also_carried_by signals syndication across outlets. It omits error behavior for an unknown id, which is the remaining gap.

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 essential framing ('One story in full') followed by a dense field inventory and a one-line instruction. The long enumeration is justified because no output schema exists, though the single run-on sentence could be trimmed slightly.

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 of describing the return shape and does so thoroughly, field by field. Only failure behavior (unknown or stale id) is left unaddressed for a simple one-parameter lookup.

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% and the schema already says the id must match 'exactly as another Mappit tool returned it.' The description's 'Pass a story id from another Mappit tool' largely restates that, so it adds only marginal meaning over structured data.

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+resource ('One story in full') and enumerates exactly what the payload contains — headline, summary, publisher, link, publication time, location, found_by, storyline, also_carried_by. This clearly distinguishes it from list_stories (singular, full detail) without needing to open either 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?

The only guidance is 'Pass a story id from another Mappit tool,' which clarifies parameter provenance but not when to choose this tool over list_stories or how to obtain a valid id in practice. Usage is implied rather than stated with alternatives or exclusions.

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