set_contact_alias

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

With no annotations provided, the description carries full burden but only states the basic action without disclosing behavioral traits. It doesn't mention whether this is a persistent change, if it requires specific permissions, what happens on invalid JID, or if there are rate limits. The description is minimal and lacks crucial operational context.

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 appropriately sized with a clear purpose statement followed by parameter documentation. The two-sentence structure is efficient, though the parameter documentation could be integrated more smoothly rather than as a separate 'Args:' section.

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 mutation tool with no annotations, no output schema, and 2 parameters at 0% schema coverage, the description is insufficient. It doesn't explain what happens on success/failure, whether the change is reversible, or how to verify the alias was set. The minimal information provided leaves too many operational questions unanswered.

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 description explicitly lists both parameters with brief explanations ('Contact JID', 'Alias to set'), adding meaning beyond the schema which has 0% description coverage. However, it doesn't provide format details (e.g., JID structure, alias length limits) or examples, leaving significant gaps in parameter understanding.

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 the specific action ('Set a local alias'), the resource ('for a contact'), and distinguishes it from its sibling 'remove_contact_alias' by specifying the opposite operation. It uses precise language that leaves no ambiguity about what the tool does.

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 implies usage context by mentioning 'local alias (nickname)', suggesting it's for personal labeling rather than system-wide changes. However, it doesn't explicitly state when to use this versus alternatives like 'show_contact' or 'search_contacts', nor does it mention prerequisites like contact existence.

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