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

Annotations already declare readOnlyHint=true, openWorldHint=false, and destructiveHint=false, so the safety profile is covered structurally. The description adds that the guidance is 'full' and 'current', but does not describe permissions, rate limits, or how the guidance is scoped, leaving behavioral context at a basic level.

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 a single front-loaded sentence with no wasted words. It immediately communicates the action and the resource.

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?

For a simple one-parameter help tool with full schema coverage and clear read-only annotations, the description is almost complete. The only missing piece is whether the returned guidance is structured or free-form, but without an output schema this is a minor gap.

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% and the single parameter is fully documented as 'The tool name to explain.' The description does not add syntax, naming conventions, or examples for the tool parameter, so it relies on the schema and meets the baseline for high-coverage schemas.

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 states a specific verb and resource: read the full current guidance for a Fathom tool. This clearly distinguishes it from action tools like fathom_remember or fathom_find, though it does not explicitly contrast with adjacent discovery tools such as platform_describe or capabilities_search.

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?

Usage is implied by the tool name and description: call it when you need guidance about a specific Fathom tool. There is no explicit when-to-use, when-not-to-use, or alternative-tool guidance, so the agent must infer the appropriate context.

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