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

Annotations only carry readOnlyHint=true; the description adds the output artifact ({ Url }), the intended consumption surface (browser/iframe), and explicitly confirms no account data is changed. It still omits things like URL lifetime/expiry or auth requirements, so it stops short of 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 tight sentences lead with the action, then the optional scoping rule, then the return/endpoint facts. No filler, and the most important information is front-loaded.

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?

There is no output schema, but the description compensates by naming the return field ({ Url }). With only two optional params and full schema coverage, an agent has everything needed to call this correctly and interpret the result.

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?

Schema coverage is 100%, so the baseline is 3, but the description adds relational semantics the schema lacks: both parameters must be supplied together to scope to one conversation thread, and textNumber must be a toll-free number. That joint-use constraint is meaningful beyond the per-field schema text.

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 artifact: generate a single-sign-on URL to the Text-Em-All conversations UI. It even names the backing endpoint (POST /v1/singlesignon/conversations) and the return shape, so an agent can distinguish it from siblings like get_authorization_token without opening the schema.

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?

Explains where the URL is meant to be consumed (browser/iframe) and gives the optional scoping condition: pass toll-free textNumber plus the other phoneNumber to target a single thread. It does not name an alternative tool or state when-not-to-use, but no sibling competes for this exact job.

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