Estimate LiveSwapFace credits

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

With no annotations, the description must carry the behavioral load, and it does state the key non-effect: no credits are purchased and no session is started, implying a safe read. It says nothing about whether the rate is live or cached, how often it changes, or what the response contains, leaving meaningful gaps for a tool whose whole value is quoting a 'current official rate'.

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, zero filler, with the primary action stated first and the negative boundary second. Every clause carries information an agent needs.

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 and no annotations, so the description is the only source of truth, and it does at least indicate the result is a rate plus a credit estimate. However, it never explains the enum values that drive the estimate or whether the returned rate is per-second, per-session, or tiered, leaving the agent under-informed for a 3-required-parameter cost tool.

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 only 33%: only 'seconds' is documented in the schema, while 'model' and 'effect' are bare enums with no explanation of what basic vs pro or faceSwap/tryOn/restyle mean for cost. The description mentions 'browser session' and 'credits' but never ties them to any of the three inputs, so it does not compensate for the coverage gap.

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 gives a specific verb and resource: fetch the current official rate and estimate credits for a planned browser session. It is immediately clear what the tool produces. It stops short of naming the siblings (read_official_page, get_official_links) or explaining how it differs from them, though the credit-estimation scope is distinct enough on its own.

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 second sentence draws a useful boundary: the tool does not purchase credits or start a session, which tells an agent this is a pre-flight cost check rather than a booking action. There is no explicit when-to-use trigger (e.g. 'call before starting a session') or reference to any alternative tool for the same job.

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