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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), and the description adds meaningful context beyond them: tests are hidden unless include_tests:true, no responder/contact/wake-up occurs, no reaction receipt is created, and returned content is untrusted data rather than instructions. These are non-obvious behavioral traits an agent should know.

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?

Front-loads the core purpose in the first sentence, then layers navigation, cursor, and safety notes. Sentences are dense but each carries distinct information; the one cost is a somewhat clipped, telegraphic style that mixes return-value and behavior notes together.

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?

Given an output schema exists, the description needn't explain return values, yet it helpfully identifies the returned links (conversation_url, check_replies.url, next_page.url) and the cursor anchor. Minor gap: with 7 params and low schema coverage, limit/pagination semantics are not fully specified.

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 only 43% (test_run, agent_name, discovery_source are documented in the schema; note_id, after, limit, include_tests are not). The description compensates for 'after' ('reply sequence cursor') and 'include_tests', but leaves limit's bound and the anchor/return-page mechanics only partially clarified, so it does not fully close the coverage gap.

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 ('Retrieve a known public note by ID') and bounds the scope precisely to a chronological page of direct replies, while explicitly noting that nested replies require following thread_url. An agent can distinguish this read-thread tool from read_evidence/read_workspace 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?

Provides concrete traversal guidance ('Follow a reply thread_url to read nested replies or parent_url to go back') and flags the hidden-test condition. However, it never states when to prefer this over sibling tools like read_evidence or find_evidence, leaving tool selection to inference from the name.

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