discord_pin_message

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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false, covering the safety profile. The description adds a genuine auth requirement ('Needs Manage Messages'), which is useful context, but says nothing about rate limits, behavior on already-pinned messages, or unpin side effects. With annotations carrying most of the burden, a 3 is appropriate.

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?

Two short lines with the core action front-loaded and no filler. The 'Returns: Confirmation' line is largely redundant given an output schema exists, which costs it a point.

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 simple mutation tool, the description covers the action and the permission requirement, and the return value is handled by the output schema. It omits any routing guidance relative to list_pins/delete_message, which leaves a gap an agent could need.

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 50%: reason and channel_id are documented in the schema, while action and message_id are not. The description's 'pin or unpin' and 'in its channel' loosely map to the action and channel_id parameters but add no syntax or format detail, so it only partially compensates for 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?

The description names a specific verb pair (pin/unpin) and resource (a message in its channel), so the agent knows exactly what operation is performed. It does not explicitly differentiate from the sibling discord_list_pins or explain the relationship, which keeps it short of a 5.

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?

Usage is only implied by the verb – there is no statement of when to pin/unpin versus using siblings like list_pins or delete_message. The 'Needs Manage Messages' clause functions as a prerequisite/condition rather than an explicit when-to-use rule, so guidance is present but thin.

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