postcard

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

With no annotations, the description carries the full behavioral burden. It discloses that output is 'human-legible' verse and is a live composition, but says nothing about read-only nature, error handling for invalid coordinates, or rate limits. It adds some context but leaves gaps for a tool with zero annotation coverage.

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 sentence plus a short qualifier, with the core capability front-loaded and no wasted words. Well sized for the tool's simplicity.

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 demo tool with no output schema or annotations, the description conveys enough to call it correctly: what goes in (a coordinate) and what comes out (a few lines of verse). Only minor gaps around coordinate format and error behavior remain.

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% for both lat and lon, so the schema contributes no meaning. The description only says 'at a coordinate,' hinting that lat/lon are geographic but adding no format, range, or ordering detail; it partially compensates but not fully.

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 states a concrete output (a few lines of live verse) and the inputs it synthesizes from (weather, nearest recent earthquake, ISS position at a coordinate), so an agent can tell it is a generative/synthesis tool. It is clearly distinct from the granular siblings like weather, earthquakes, and iss, though it never explicitly says it aggregates them.

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 phrase 'nice for demos' implies a light, presentational context, which is weak usage guidance. There is no statement of when to prefer this over the raw weather/earthquakes/iss siblings, and no when-not guidance.

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