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

Annotations only give destructiveHint=true; the description carries the real burden and delivers: it warns that Account Match may merge the new account into an existing one with the same name/email, states it returns the new id, and names the underlying POST /accounts call. The merge side effect is exactly the kind of non-obvious behavior an agent needs, though auth/permission requirements are not mentioned.

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 sentences with zero waste: the type distinction is front-loaded, the merge caveat follows, and the return/endpoint close it out. Every clause earns its place.

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 19 parameters fully covered by the schema and no output schema, the description covers the remaining gaps: what it creates, the merge risk, and the returned id. It is essentially complete, with only minor omissions like permissions or partial-failure behavior.

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 the schema already documents all 19 fields with meanings, including the company_name-required-for-COMPANY relationship. The description repeats some of this (company_name, optional primary contact) without adding format or syntax beyond the schema, so baseline 3 applies.

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 resource ('Create a constituent account') and immediately disambiguates the two account flavors (INDIVIDUAL vs COMPANY) with the fields each implies. This cleanly separates it from siblings like neon_update_account and neon_get_account.

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?

Explicitly directs the agent to check neon_list_accounts by email first because of Account Match merging, which is actionable when-to-use guidance with a named sibling. It stops short of stating when-not to use it (e.g., prefer neon_update_account for an existing account), so it is clear but not exhaustive.

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