start_meta_login

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

There are no annotations, so the description carries the full burden, and it does disclose the key behavioral facts: the call yields a login URL, it requires META_APP_SECRET server-side configuration, and it must be followed by get_meta_auth_status. It does not say whether the call blocks, whether the URL expires, or what happens if login is already in progress.

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?

Four short sentences, front-loaded with the purpose, then the config prerequisite, then the required next call. No filler and nothing repeated from the schema.

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 one-parameter auth-initiation tool with no annotations and no output schema, the description covers purpose, trigger, return value, configuration prerequisite, and next step. Only edge-case behavior (re-invocation while pending, URL lifetime) is missing.

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 description coverage is 0%, so the description must explain the single parameter, and it does: app_id is public, optional, and falls back to META_APP_ID when configured. The digit-only pattern is left to the schema, which is a minor omission well within the schema's role.

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 opens with a specific verb and resource: 'Start Meta browser login'. It is immediately distinguishable from the sibling get_meta_auth_status, whose job is to poll status rather than initiate the flow.

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?

It states the trigger ('when the user wants to sign in') and the required follow-up ('After browser approval call get_meta_auth_status'), which effectively routes the agent into the correct two-step sequence. It stops short of any when-not guidance (e.g. don't start a second login while one is pending).

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