pinChatMessage

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

No annotations are present, so the description carries the full disclosure burden. It discloses the mutating nature of the operation, chat-type-dependent authorization requirements, and the return contract (True on success). It stops short of describing failure behavior or error conditions, which is the main gap.

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 sentences, front-loaded with the core action and followed by the essential permission clause. No filler; every sentence earns its place.

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?

Covers the action, authorization prerequisites, and return value, which is the essential set for a mutating tool with no output schema. Minor gaps: no statement about failure modes or message-existence requirements, but the schema fully documents the parameters, making the tool safely callable.

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 every parameter is already documented in the input schema. The description adds no parameter-specific detail beyond what the schema provides, so the baseline of 3 applies.

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 states a specific operation — adding a message to the pinned list of a chat — with a clear verb and resource. It distinguishes itself from sibling tools like unpinChatMessage and unpinAllChatMessages without needing to read their schemas.

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 prerequisite context: non-private chats require administrator rights (can_pin_messages in supergroups, can_edit_messages in channels), and private chats are exempt. It does not explicitly name alternatives or state when-not-to-use, but the permission conditions give an agent the information needed to decide whether the call will succeed.

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