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

Annotations already declare read-only, idempotent, and non-destructive behavior. The description adds useful behavioral detail beyond annotations: output is capped at 32000 characters and omitting heading_id reads from the beginning. This gives the agent a clearer model of the tool's runtime behavior.

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, information-dense sentence with no filler. It front-loads the core behavior and then adds the two most important behavioral caveats (omitting heading_id, output cap). Every 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?

The tool has a simple read-only profile, a fully documented input schema, and an output schema. The description covers the key behavioral nuance (section vs. start, character cap) that is not fully captured by structured fields. Nothing essential is missing for an agent to invoke it correctly.

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 schema already fully documents all three parameters. The description reinforces the heading_id optionality and the 32000-character cap, but does not add meaning materially beyond the schema. Baseline 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 uses a specific verb ('Read') and a precise resource ('one bounded Markdown section by heading id'), which clearly distinguishes it from siblings like read_document and search_documents. It also explains the key optional behavior of omitting heading_id. This is a clear, non-tautological definition.

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 implies usage: read a specific section by heading_id, or from the beginning if omitted. However, it does not explicitly contrast with read_document or state when to prefer this over the sibling tools. The guidance is functional but relies on the tool name and sibling context.

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