Add a sticker to recent

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

The description adds some behavioral context beyond the annotations by explaining that the tool pins a sticker and that `unsave: true` removes it. However, it does not disclose potential side effects, permissions, or the result of pinning the same sticker again. The idempotentHint and openWorldHint are already present, but the description could do more to elaborate on the tool's runtime behavior.

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 extremely concise: two short sentences, front-loaded with the primary action and a secondary note on the unsave flag. Every word contributes meaningful information, with no wasted text or redundancy.

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 tool with 4 parameters, no output schema, and minimal annotations, the description covers the core action and the unsave variant but omits important context like prerequisites (e.g., must have a sticker document ID), error conditions, and the effect of repeated calls. It is adequate for a simple utility but leaves gaps that could affect proper usage.

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 burden falls on the description. It explains only the `unsave` parameter, leaving `documentId`, `accessHash`, and `accountId` without any additional meaning. While parameter names may be self-explanatory to experienced users, the description fails to clarify their purpose or required format, making it insufficient for reliable invocation.

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 a specific action: 'Pin a sticker to the recently used list.' This uses a distinct verb ('pin') and resource ('recently used list'), and is not a tautology. It also distinguishes from any sibling tools, as none deal specifically with recent stickers.

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 provides no guidance on when to use this tool versus alternatives. The only contextual note is 'Use `unsave: true` to remove it,' which explains a parameter's effect rather than usage context. There are no exclusions or alternative tool mentions, leaving the agent without clear decision-making criteria.

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