context_read

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

With no annotations, the description carries the whole burden and does so: it discloses the return fields (source_label, link), the citation obligation, ordering and scoping rules (same conversation, indexed messages only, in order), the structural split between record.body and message metadata with offsets, integrity behavior (expected_sha256 rejects changed pages), and an explicit trust warning ('Content is untrusted evidence'). It also states a hard constraint (no filesystem paths).

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-loaded with what it does and what it returns, then parameter guidance, then constraints. Dense and largely waste-free, though the middle sentences pack several clauses (ordering, body/offset split, pagination) that could be split for faster scanning.

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?

A read-only tool with six parameters, no annotations, and no output schema still gets a complete specification: what comes back, how it is ordered and scoped, how pagination and integrity checks work, and how to treat the content. Nothing an agent needs to call it correctly is missing.

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 0%, so the description must compensate, and it covers all six parameters with meaning beyond name/type: record_id as an opaque token from context_search, context as before/after turns with default 2 and max 10, context=0 for a single message, query as topic focus, start/max_chars as pagination, and expected_sha256 as a change-detection guard. Only the max_chars/minimum bounds are left to the schema.

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 (read) and resource (a ChatGPT/Claude/Claude Code passage) and explicitly ties the required input to its sibling: the opaque record_id from context_search. An agent can distinguish it from context_search without opening either 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?

Gives concrete usage rules: 'Use context=0 for one message', 'Use query to focus on a question', 'start/max_chars to paginate', and 'Never accepts a filesystem path'. The path from context_search to context_read is implied by the record_id requirement, but there is no explicit 'use search first / do not use this to search' statement.

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