discord_fetch_pinned_messages

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

The readOnlyHint annotation already establishes safety, and the description's 'Read-only' line confirms it without adding new behavioral depth. It adds the return shape and pinned-message scope, but does not address pagination, rate limits, permissions, or failure behavior. This is acceptable but not exceptional given annotations already cover the key safety trait.

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?

Three short sentences, each earning its place: the operation, the return shape, and the pointer to the mutation sibling. It is front-loaded with the core purpose and contains no filler or repetition.

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 single-parameter read-only tool with a full input schema and output schema, the description covers everything needed: what it lists, what it returns, that it is safe, and which sibling to use for modifications. No critical information 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 100% and the single parameter channel_id is already described as a snowflake ID for a channel or thread. The description adds no additional parameter-level meaning, so the schema carries the full weight here, matching the baseline of 3.

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 and resource: 'List all pinned messages in a channel.' It clearly identifies the tool's scope and differentiates it from mutation tools like discord_pin_message by explicitly stating this is read-only and directing to discord_pin_message for changing pins.

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 explicitly states when to use the tool (to list all pinned messages) and gives an alternative for a related but different need: 'Use discord_pin_message to change which messages are pinned.' This is direct and leaves no ambiguity about the read-only intent.

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