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

Annotations already declare readOnly, idempotent, and non-destructive behavior, so the bar is lower. The description adds value by disclosing that the tool returns self-serve paths, tiers, monthly limits, and explicitly flags that some answers are estimates rather than guaranteed figures.

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?

The description is a single dense sentence that front-loads the core purpose and ends with explicit call triggers. It is slightly wordy — 'how to go further than this free rung' repeats the title concept — but every phrase adds meaning and there is no filler.

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 parameterless, read-only informational tool with full annotation coverage, the description is complete. It tells the agent what topic is covered, what content areas are included, and exactly which user questions should route here, leaving no selection ambiguity.

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?

With zero parameters, the input schema carries no semantic burden, so the baseline is 4. The description further clarifies what the no-argument call will return at a content level, though it does not specify exact output formatting.

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 names the resource (finology's self-serve service tiers) and the specific content: advisor app trial, developer/operator sandbox key, keyed MCP and REST endpoints, auth header, tiers, monthly limits, and what is an estimate. It also gives explicit call triggers, making it unmistakeable what the tool is for and clearly distinguishing it from the student-loan sibling tools.

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 provides explicit when-to-call conditions: when a user asks how to get a key, what it costs, whether numbers are warranted, or how to integrate into their own product. Although it does not name alternative tools, the sibling context makes them obviously unrelated, so no exclusion is needed.

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