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

With no annotations provided, the description carries the full behavioral disclosure burden and does so thoroughly. It explains the authentication behavior (bearer JWTs with iss equal, matching aud, verified against jwks_url), implies idempotent register-or-update semantics, states the per-tenant limit, and names a precise error condition (issuer_already_registered).

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 dense, front-loaded sentences: the first states the action and core verification logic, the second adds constraints and an error condition. Every clause earns its place with no redundancy or boilerplate.

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 4-parameter mutating tool with no output schema and no annotations, the description covers the operation's purpose, authentication pipeline, limits, and likely failure mode. The optional tenant_key parameter is fully documented in the schema. It is slightly thin on what the response returns and what exactly 'update' changes, but nothing essential to invoking the tool 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 description coverage is 100%, so each parameter is already documented individually. The description adds value by tying the parameters together into the verification flow (iss matches the issuer, audience must match, jwks_url is used for verification) and by explaining uniqueness behavior. It does not add tenant_key semantics, but the schema already covers those fully.

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 'Register (or update) an OAuth issuer for this tenant' – a specific verb and resource – and then details the exact JWT verification semantics (iss, aud, jwks_url). This is clearly distinct from sibling tools host.oauth.issuers (list) and host.oauth.issuer_remove (delete), so an agent can differentiate them without opening schemas.

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?

The description clearly frames the use case: register or update an OAuth issuer for tenant authentication, with constraints (max 3 per tenant, uniqueness conflict) that inform decision-making. However, it does not explicitly reference sibling alternatives or state when not to use this tool, so it stops short of full routing guidance.

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