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

Goes well beyond the annotations: it discloses that unpublished facts are omitted, that hours/routes are quoted as published rather than promised, that no personal data is accepted and nothing is sent, and that non-card clients get a text fallback. These are exactly the behavioral traits an agent needs and that readOnlyHint/idempotentHint do not convey.

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?

Front-loaded with the usage trigger, then follows with scope and behavioral caveats. It is dense and slightly long-winded in the middle clause, but every sentence contributes a distinct fact rather than repeating the schema or annotations.

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 an output schema present, the description need not explain return values, yet it still summarizes card contents and the text fallback. Combined with the annotation profile, nothing an agent needs to select or call this tool 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?

Zero parameters, so the baseline is 4; the description reinforces this with 'Takes no arguments', confirming the empty schema. No additional parameter detail is possible or needed.

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 and resource ('show contact options as a card') and immediately distinguishes it from the sibling get_contact_options by noting it presents the same facts in card form. An agent can tell the two apart without opening either schema.

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 opening clause gives a clear trigger ('when a person asks how to get in touch ... and would like to see it as a card'), and the sibling get_contact_options is named as the source of the same facts. It stops short of explicitly stating when to prefer get_contact_options instead, leaving the converse to be inferred.

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