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

Annotations already declare the safe/read-only profile, so the bar is lower. The description adds value by naming the accepted input formats and, importantly for a tool with no output schema, disclosing that output is 'normalized UTC timestamp forms.' Error handling and ambiguity resolution for 'auto' remain undisclosed.

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?

A single, front-loaded sentence that packs the input formats and the output form with zero filler. Every clause earns its place.

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 two-parameter, single-purpose conversion tool with full schema coverage, this is nearly complete. Since there is no output schema, the description carries the output-form explanation, but it leaves 'auto' detection and invalid-input behavior unspecified.

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 100%, with the 'from' enum values and 'value' already documented in the schema. The description restates the input formats but adds no syntax, defaults, or examples beyond what the schema provides, so the baseline 3 is appropriate.

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 (Convert) and resource (timestamps) and enumerates the accepted input formats (Unix seconds/milliseconds, RFC3339, ISO). This clearly distinguishes it from siblings like base64_convert or url_parse, though it does not explicitly name an alternative.

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?

Usage is implied by the description and the 'from' enum, but there is no explicit when-to-use, no mention of the 'auto' default behavior, and no exclusion against adjacent tools. An agent can infer this converts timestamps but gets no routing guidance.

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