capability_probe

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

With no annotations provided, the description carries the full burden and does substantial work: it discloses that data comes from a static dated fixture that is '[verify]-flagged' (i.e., potentially stale), that no live Graph API call occurs, and precisely what the failure-simulation flag does to modes. It stops short of covering auth/permission needs or error behavior, but this is well above the bar for an unannotated tool.

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 densely packed sentences, front-loaded with what is returned and the crucial 'no live API call' caveat before the optional flag's behavior. No filler, though the parenthetical jargon ('dated, [verify]-flagged', 'spec SS9') costs some readability.

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, the description must convey the return shape, and it does — per-capability modes for an eligible professional account per spec SS9 — plus the behavioral effects of the flag. It lacks detail on the exact structure of the matrix or what happens on failure beyond the simulated mode collapse, but nothing an agent needs to invoke it correctly 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 coverage is 0% and the single parameter has no schema-level description, so the description must compensate — and it does, explaining that simulate_probe_failure=true triggers the family downgrade rule with concrete outcomes (write modes collapse to prep, own-engagement to COMMUNITY_PREP). The implicit default (false = static declaration read) is inferable but never stated outright.

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 names a specific verb and resource ('Return Aperture's capability matrix') and scopes it to per-capability modes for an eligible professional Instagram account per spec SS9. It is clear what is produced, though the heavy jargon ('[verify]-flagged', 'Aperture') and the absence of any differentiation from siblings like variant_build or preview_pack keep it from a 5.

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 a useful usage constraint upfront — 'NO live Graph API call is made in v0.1' — and explains the condition for the one optional flag ('Pass simulate_probe_failure=true to exercise the family downgrade rule'). However, it never says when to reach for this tool versus the sibling tools or which situations it is not appropriate for, leaving usage largely implied.

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