send_message

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

Annotations already signal that this is a non-read-only, non-destructive operation. The description adds the behavioral detail of supporting HTML/Markdown/MarkdownV2 formatting, which is useful context, but it omits broader behavioral aspects like permission requirements or potential side effects. This is acceptable given the annotations, but it does not go far beyond them.

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 two short, front-loaded sentences with no filler or redundant phrases. Every word contributes to understanding the tool's core purpose and formatting capability.

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?

With 13 parameters and no output schema, a one-sentence description is minimal but sufficient for basic use (sending text to a chat). It does not explain optional parameters or return behavior, but the schema partially covers some properties. This is a minimum-viable description for the tool's complexity.

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 only 54%, so the description should compensate for undocumented parameters. It only restates that a chat is the target and that formatting modes are HTML/Markdown/MarkdownV2, which duplicates the parse_mode enum. It does not clarify optional parameters like reply_markup, entities, or link_preview_options, nor does it add value beyond the schema.

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 begins with the specific verb 'Send' and clearly identifies the resource as 'a text message to a chat,' which distinguishes it from sibling tools like send_photo or send_document. The mention of formatting modes further clarifies its intended scope.

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 offers no guidance on when to use send_message versus alternatives such as send_photo, edit_message_text, or send_message_draft. It does not state exclusions or explicitly name alternative tools for other message types or actions.

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