tg_contacts

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

Annotations already establish readOnlyHint, openWorldHint, idempotentHint, and non-destructive behavior. The description adds valuable behavioral constraints: query only applies when kind='all', birthdays are date-sorted, and top is ranked by Telegram itself. No contradiction with annotations; these details go beyond what annotations provide.

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 compact and well-structured: a one-line opener followed by a tidy three-item arg list. Each kind line adds functional meaning, so every sentence earns its place without fluff or 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?

For a zero-required-parameter, read-only tool with no output schema, the description fully covers all inputs and all kind variants, including sorting and intended use cases like birthdays. An agent can correctly select and invoke any mode based solely on this description.

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% and there are no enumerations, so the description carries the full parameter-documentation burden. The 'Args' section defines all three parameters: query (name/username filter, scoped to all), limit (row count), and kind (all five accepted values with their precise meanings). This fully compensates for the schema's silence.

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 opening phrase 'Your contacts, or a slice of them' names the resource but lacks an explicit verb like 'list' or 'get'. However, the kind parameter enumerates five concrete retrieval modes (all, birthdays, top, online, blocked), making the tool's purpose clear and distinguishable from siblings such as tg_block or tg_person.

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 kind descriptions implicitly route usage—'birthdays' explicitly answers 'whose birthday is coming up', 'online' selects currently online contacts, and 'blocked' is the block list. But the description never names alternatives or states when not to use this tool, such as using tg_person for a single contact's details, so the guidance is implied rather than explicit.

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