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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds a little behavior by naming what comes back (status, picture, figures), but says nothing about failure modes, missing conversions, or cost/latency for requesting the picture.

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?

Two short sentences, front-loaded with the caller restriction followed by the return content. Nothing is redundant, though the idiosyncratic wording ('the VecSnap card') costs clarity without adding length savings.

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?

There is no output schema, so the description should carry return-value meaning; it names three categories of output but leaves the 'card' concept and the picture flag unexplained. For a simple two-parameter read tool this is close to adequate but not fully self-contained.

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 coverage is 50%: conversion_id is well documented in the schema itself, while want_picture has no schema description. The phrase 'its picture' weakly implies the optional picture flag, but the description never explains what toggling it does, so it only partially compensates.

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 says it 'answers how a conversion stands, its picture and its figures,' which hints that it returns status plus visual/numeric data for a conversion. However, the verb and resource are never stated plainly ('card' is undefined jargon), so an agent must infer that this is a read of conversion state rather than something card-specific.

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?

It states a caller restriction ('Only the VecSnap card calls this') but gives no when-to-use guidance relative to siblings like get_conversion or get_svg, and no exclusions or prerequisites. The agent is told who calls it, not when it should be chosen.

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