Read messages

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

The description adds useful behavioral context beyond the readOnlyHint annotation: it specifies the digest content, oldest-first ordering, and paging. However, the reference to 'next_before' is inconsistent with the actual parameter 'before', which could mislead an agent about the API contract.

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 concise, with two sentences that front-load the core purpose and include useful digest details. The incorrect parameter name is a content issue rather than a structural one, so conciseness itself is handled well.

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 description covers the return shape (author, time, content, attachments, reactions, reply references) and clarifies ordering and paging. However, the incorrect paging parameter name and lack of fallback guidance leave the description incomplete for a tool with no output schema and no error handling notes.

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 a baseline of 3 is warranted. However, the description not only adds no meaningful parameter semantics but incorrectly mentions 'next_before' instead of the actual 'before' parameter, potentially confusing the agent. This negative contribution lowers the score.

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 clearly states the tool reads recent messages from a channel and provides a digest with fields like author, time, content, and reactions. It distinguishes itself from get_message (singular) but doesn't explicitly differentiate from search_messages, though 'recent messages' and 'digest' imply a list operation.

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 gives a paging hint ('Use next_before to page further back') but provides no guidance on when to choose this tool over siblings like search_messages or get_message. There is no mention of use cases or exclusions.

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