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

readOnlyHint=true already declares the safety profile, so the description only needs to add value — which it does by disclosing that the call is scoped to "these credentials" and is cheap enough to use as a credential/org-ID sanity check. No permission, cost, or side-effect details beyond that, but none are needed for a zero-arg read.

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, front-loaded with the purpose and followed by the practical use case plus the endpoint. Every clause earns its place with no repetition of the title.

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 read tool with no output schema, the description fully compensates by listing the returned fields and the underlying endpoint, so an agent knows exactly what it gets back without needing a schema.

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 no parameters, so there is nothing for the description to disambiguate; 4 is the baseline for a zero-parameter tool.

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 (fetch) and resource (the organization these credentials belong to), and enumerates the returned fields (name, org ID, app URL), so it is immediately distinguishable from the account/activity/campaign siblings. The API path is also named.

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?

"A cheap way to confirm the org ID and API key work" gives a concrete when-to-use scenario (credential validation) that an agent can act on. It stops short of explicitly stating when not to use it or naming an alternative, but the context is clear.

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