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

With no annotations, the description carries the full burden and does well: it discloses the auth prerequisite (connected Firecrawl account), that the action is an interactive UI surface rather than a data return, and that it can attach context to a conversation (a side effect). It doesn't say what the call returns or what happens if the account isn't connected, which keeps it from a 5.

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?

Three short sentences, front-loaded with the action and capabilities, then the prerequisite, then the sibling routing. Every sentence carries distinct information with no repetition of the name or 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 zero-parameter, no-output-schema UI tool, the description covers purpose, prerequisite, and alternative, which is nearly everything an agent needs. A small gap remains around outcome (does it return a URL/handle, and does it fail without a connected account), but this is minor given the tool's simplicity.

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 takes zero parameters, so the baseline is 4; there are no argument semantics for the description to explain. It correctly adds no redundant parameter talk, though it also can't be credited with compensating detail.

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?

States a specific verb and resource ('Open the Firecrawl sidebar') and enumerates three concrete capabilities: browsing Alexandria providers, attaching tool context to a conversation, and viewing credits/usage. It is clearly separable from siblings like firecrawl_credit_usage or firecrawl_provider_directory because it is the interactive-UI entry point rather than a data endpoint.

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?

Names an explicit alternative and the condition that selects it ('Use firecrawl_credit_usage for data-only reporting'), and states the prerequisite ('Requires a connected Firecrawl account'). It stops short of saying when an agent should prefer opening the sidebar at all (e.g., only when the user wants interactive browsing), leaving that inference to the caller.

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