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

With no annotations, the description carries full burden. It discloses the primary behavior (opening a browser page), but does not mention potential side effects, prerequisites (e.g., login), or what happens after navigation. Adequate but lacks depth for a complete behavioral 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 sentences, front-loaded with the action and purpose. The second sentence efficiently lists plan limits. Every word contributes value; no filler or repetition.

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?

The description covers the essential purpose and provides plan details, which is sufficient for a simple browser-opening action with no parameters or output schema. It does not mention post-navigation steps (e.g., manual purchase), but that is implied and minor.

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?

The tool has zero parameters and schema coverage is 100% (empty schema), so the description does not need to elaborate on parameters. Baseline for 0 params is 4, and the description adds useful plan information, slightly exceeding the baseline.

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 clearly states the tool opens the GlassyPic pricing page to upgrade the plan for more credits, using specific verb 'open' and resource 'pricing page'. It is distinct from sibling tools (optimize_image, status) and lists the available plans, removing ambiguity.

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 description implies when to use this tool: when the user wants to upgrade for more credits. It also provides plan tiers and limits, offering context for the decision. However, it does not explicitly state alternatives or exclusions, hence not a 5.

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