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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safe-read profile is covered. The description adds that the row includes artifact and routing-surface status, giving useful return context, but does not discuss not-found behavior or access requirements; the annotations carry most of the safety burden.

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?

Single sentence, front-loaded with the action and resource. The opening repeats the title almost word-for-word, which is slightly redundant, but there is no filler and the added clause earns its place.

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 one-parameter read-only tool with an output schema and safety annotations, the definition is largely complete. The only gap is the lack of explicit guidance on missing slugs or when to prefer list_guides, both of which are minor for this simple 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% for the single required slug parameter, and the description only restates that lookup is by slug. It adds no new semantic detail beyond the schema, so the baseline of 3 applies.

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 ('Get'), a specific resource ('one guide's registry row'), and the lookup key ('by slug'), clearly distinguishing it from the sibling list_guides. It also mentions what is included in the result (artifact + routing-surface status).

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 makes clear this is for retrieving a single registry entry by slug, which implies a targeted lookup rather than enumerating guides via list_guides. It does not explicitly name alternatives or exclusion cases, but the context signals and 'one guide' phrasing provide sufficient guidance.

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