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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds value beyond that by disclosing the return format (markdown) and the two retrieval modes. It omits error behavior for an invalid slug or unmatched heading, which keeps it out of 5 territory.

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?

Two short sentences with no filler: the capability comes first, then the sequencing hint. Every clause earns its place, and the secondary routing advice is placed last where it does not delay the core purpose.

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 two-parameter read-only tool with no output schema, the definition covers purpose, mode selection, output format, and prerequisite. The only meaningful gap is failure behavior when the slug or heading does not resolve, which an agent would otherwise have to infer.

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 50%: 'section' is documented in the schema while 'slug' is bare. The description clarifies the section case ('one section of it by heading'), which usefully matches the heading-text semantics, but 'by slug' adds little beyond restating the parameter name. Reasonable compensation, not full.

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 ('Get the full text ... of one guide') and quantifies scope ('one guide'), including the two retrieval modes: whole document by slug or a single section by heading. The added '(markdown)' even pins the return format, so an agent knows exactly what it gets without opening the 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?

'Use after search_guides' explicitly names the sibling that produces the slug this tool consumes, giving a clear ordering rule. It stops short of stating when not to use it or what to do if the slug is unknown, so it lands at 4 rather than 5.

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