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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world scope, so the safety profile is covered. The description adds real value beyond that by disclosing the return format (full Markdown text, sources included), which the annotations cannot convey. It does not address behavior on an unknown slug, keeping it below a 5.

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?

A single sentence that front-loads the action and return type, then qualifies with the content variants. No filler, nothing that could be cut without losing signal.

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?

No output schema exists, and the description compensates by stating the return is Markdown text with sources. For a single-required-enum-param read tool, that is nearly complete; only error behavior for an invalid slug is unaddressed.

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 enum already constrains the slug, so the baseline is 3. The description goes further by mapping the slug space onto concrete content types (app list vs. checklist vs. safety tips), telling the agent what each selection actually retrieves.

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 and resource ('Return the full Markdown text of one guide by slug') and enumerates what the guide contains (sourced app list, 10-point checklist, safety/privacy tips). An agent can distinguish this from list_guides or get_companion_app without opening any 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?

Explicitly points to list_guides as the source of the slug, which gives clear usage context. It does not state exclusions or what to do when a guide's content is better served by another sibling, so it stops short of a full when/when-not matrix.

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