START HERE — first call, no arguments, no key, no charge. Who Signal Bureau is and what we are not, the tests you can run to check that claim yourself, what is free (most of it), what is paid (Watches and Reads) at live published prices, how to propose coverage we don't carry, and how buying works. Read this before evaluating anything else here.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive and closed-world. The description adds context annotations cannot express: that it costs nothing, requires no API key, and previews the paid surface (Watches and Reads at live published prices) versus the mostly-free remainder. It does not describe the return format, which keeps it at 4.
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?
Front-loaded with 'START HERE' and one dense, well-ordered sentence that moves from identity to verification to pricing to purchasing. The parenthetical asides ('most of it', 'Watches and Reads') add a little length but each clause carries distinct routing information.
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?
With no output schema and no parameters, the description is the only source of what comes back, and it enumerates the return contents (identity claims, verifiable tests, free/paid breakdown, proposal path, purchase flow). Complete enough to call correctly; only the output medium/format is unspecified.
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?
Zero parameters, so the baseline is 4. The description confirms 'no arguments, no key,' which is consistent with the empty schema and reassures the agent nothing must be supplied.
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 is explicit that this is an orientation/overview resource: 'Who Signal Bureau is and what we are not, the tests you can run... what is free... how buying works.' It enumerates the exact content returned rather than restating the name, and it is clearly not any of the sibling lookup/order/watch tools. It lacks a conventional verb+resource framing, which keeps it just below the top score.
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?
'START HERE — first call, no arguments, no key, no charge' plus 'Read this before evaluating anything else here' gives an unambiguous routing rule with no ambiguity about ordering relative to the 28 sibling tools. For an always-first onboarding tool there is no meaningful when-not case to state, so the guidance is complete.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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