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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, covering the safety profile. The description adds useful behavioral context by specifying the output is the document 'in full as plain text,' which goes beyond the annotations, though it does not mention error behavior or permissions.

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 tightly written sentences with zero filler. The core purpose and input method are front-loaded, and the examples are compact and useful without bloating the definition.

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 read tool with rich annotations, full schema coverage, and no output schema, the description is nearly complete: it states the plain-text return format and how to supply the document identifier. It could be slightly more explicit that exactly one of id or url is required, since the schema marks neither as required.

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%, so the baseline is 3. The description adds concrete id format examples ('blog/erasmus-2026-guide', 'city/berlin', 'refund-policy') and notes the URL domain, providing syntax guidance beyond the schema's basic field descriptions.

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 one document in full as plain text.' It enumerates document types (blog guide, city guide, FAQ, pricing, policy) and explicitly ties the id back to search_docs, distinguishing it from the sibling search tool.

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?

It clearly indicates the input source ('Pass the id from search_docs or its URL'), implying this tool is used after discovering documents via search_docs. However, it does not explicitly state when not to use it or contrast it directly with search_docs in a usage rule.

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