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

Annotations already establish this as a safe, read-only, idempotent, closed-world call. The description adds genuinely useful context beyond that: it must be called first, once per task, and enumerates the contract contents (blocks, inline marks, nesting, limits, uploads, error recovery, presets, next step). It stops short of stating caching or token-size characteristics of the returned contract.

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 sentences, all front-loaded: the imperative call-first directive leads, followed by what Postlyra produces and what the return payload contains. Every sentence carries distinct information with no 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?

An output schema exists, so return values need not be detailed, yet the description still summarizes the contract's scope and adds the sequencing rule ('first, once per task'). Nothing an agent needs to invoke this correctly 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?

The tool takes zero parameters, so per the rubric the baseline is 4. There is nothing for the description to clarify beyond the (empty) schema, and it correctly signals a parameterless call.

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?

States a specific verb+resource (get Postlyra formatting capabilities / RichDocument contract) and precisely scopes what it returns. It is clearly distinguishable from the neighboring post/workspace/template mutation tools, none of which expose formatting contracts.

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?

Explicit when-to-use: 'call it FIRST, once per task' when composing or formatting any post, and a when-not-to-look-elsewhere note ('Telegram MarkdownV2/parse_mode documentation is not needed'). It does not name sibling alternatives, but no real alternative exists for this prerequisite lookup, so the gap is minor.

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